The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
A film recorder is normally used to record digitally processed image data on photographic film material in order ultimately to be able to show the motion picture film or a copy prepared from it in the cinema. It is important in this connection that the image position of sequential individual images remains as constant as possible since otherwise the perceived image moves on projection in the cinema. It is also particularly important with a film recorder of this type that a constant spacing is maintained between exposed picture elements adjacent to one another; otherwise, perceivable differences in intensity can arise in the exposed image which make themselves noticeable as a stripe pattern, for example in an image exposure taking place line by line. Perforation holes, which are formed at one or both longitudinal sides of the film, are used for the positioning of the film. The image position perceived in the cinema is therefore the position of the image relative to the position of the perforation holes. To ensure a good relative image position, registration pins are usually introduced into the perforation holes and the film is positioned thereby.
It is generally possible to distinguish between film recorders which expose an image while the film is stationary and those which write the image line for line while the film is being moved. In the latter types, in particular laser film recorders, the film is fixed in a film holder on a linear guide, for example using registration pins. After the introduction of the registration pins into the perforation holes, the linear guide accelerates to the correct speed for the exposure of an image. The exposure then takes place line by line at a constant speed of the linear guide. Subsequently, the linear guide is braked again, the registration pins are removed from the positioning holes and the linear guide is moved back to the starting position. A high image position precision, however with a low throughput (expose images per time unit) is achieved by this design principle (linear guide with pin registration), since no images are exposed during the steps of accelerating, braking and moving back the linear guide.